From: mdiam <Maurice.Diamantini@...>
Date: 2008-08-05T20:48:33+09:00
Subject: Re: Matrix class: How to set a single element ?

Redirect to fortan just because you need some float usage
is a bad idea : it's a true argument to make switching
to piton...

But yes, if you have to manipulate matrix with billion
of elements, then you should do some fortan (... ruby binding) !

Some month ago I also had such a need.
As mentioned above, I had to reopen the Matrix class and
add several methods:

class Matrix
    def dump(firstLine = "")
        str = ""
        if firstLine != ""
            str << firstLine << "\n"
        end
        for i in 0...self.row_size
            space = ""
            for j in 0...self.column_size
                str << space << self[i,j].to_s
                space = " "
            end
            str << "\n"
        end
        return str
    end
    # La classe Matrix est immutable, or je veux pouvoir écrire :
    #   m[i,j] = v
    #
    def []=(i, j, v)
        @rows[i][j] = v
    end
    # Il n'y a même pas de constructeur pour une matrice
rectangulaire : bouhhh
    # Le prefixe "self." permet de déclarer une méthode de classe
    def self.create(nbRows, nbCols, value)
         return Matrix.rows(Array.new(nbRows, Array.new(nbCols,
value)))
    end
end